A: If we are talking state actors, like CIA? Sure it can and has been done. The Pegasus malware has been in the news lately for doing just that. if you are talking hackers or high-level organized crime? There has been no evidence of it ever done.
But, now that we have proof of concept (Pegasus), it is sure to happen sooner rather than later.
The good news is that, at least as of now, it is extraordinarily expensive to design such a tool. This is what has limited release to only very high value targets. And as soon as it was discovered, OS updates were released to block it.
